Current Conditions

Thornhill, Ontario

70°F21°C
Partly Cloudy

Wind

NNE 11 mph17 km/h

Humidity

44%

Cloud Cover

54%

As of Sunday, September 27, 2026 at 1:23 PM EDT

Today's Outlook

Day

Mostly cloudy and warm, with a high of 72°F22°C and morning low of 53°F12°C. Breezy from the NNE at 11 mph17 km/h. Dry air.

Night

Overcast, with a low around 61°F16°C. Breezy from the NE at 7 to 8 mph11 to 12 km/h.

7-Day Forecast

DayConditionHigh (°F)Low (°F)Precip (mm)Cloud Cover (%)Wind (mph)
Partly CloudyHigh 72°F22°CLow 53°F12°CPrecip 0 in0.1 mm9%Cloud 66%Wind NNE 9 mph15 km/hSunday: Mostly cloudy and warm, with a high of 72°F22°C and morning low of 53°F12°C. Breezy from the NNE at 11 mph17 km/h. Dry air. Sunday Night: Overcast, with a low around 61°F16°C. Breezy from the NE at 7 to 8 mph11 to 12 km/h.
DrizzleHigh 67°F19°CLow 56°F14°CPrecip 0.04 in0.9 mm25%Cloud 83%Wind N 6 mph10 km/hMonday: Overcast and mild, with a high of 67°F19°C and morning low of 56°F14°C. Breezy from the N at 6 to 8 mph10 to 13 km/h. 22% chance of drizzle in the morning. Monday Night: Overcast, with a low around 57°F14°C. Breezy from the N at 6 to 8 mph10 to 13 km/h. 25% chance of drizzle overnight.
Partly CloudyHigh 69°F21°CLow 57°F14°CPrecip 0 in0.1 mm1%Cloud 65%Wind S 5 mph9 km/hTuesday: Mostly cloudy and warm, with a high of 69°F21°C and morning low of 57°F14°C. Light wind from the S around 5 mph8 km/h. Tuesday Night: Mostly cloudy, with a low around 58°F14°C. Breezy from the S at 6 to 7 mph9 to 11 km/h.
DrizzleHigh 69°F21°CLow 58°F15°CPrecip 0.04 in0.9 mm23%Cloud 97%Wind SSW 8 mph13 km/hWednesday: Overcast and warm, with a high of 69°F21°C and morning low of 59°F15°C. Breezy from the SSW at 8 to 10 mph13 to 16 km/h. 15% chance of drizzle in the afternoon. Wednesday Night: Overcast, with a low around 58°F15°C. Breezy from the SSW at 8 to 10 mph13 to 16 km/h. 23% chance of drizzle in the evening.
Light RainHigh 73°F23°CLow 64°F18°CPrecip 0.17 in4.2 mm36%Cloud 92%Wind WSW 11 mph18 km/hThursday: Overcast and warm, with a high of 73°F23°C and morning low of 65°F18°C. Breezy from the SW at 11 to 12 mph18 to 20 km/h. 31% chance of light rain in the morning. Thursday Night: Overcast, with a low around 64°F18°C. Breezy from the WSW at 10 to 11 mph17 to 18 km/h. 36% chance of light rain overnight.
Light RainHigh 64°F18°CLow 54°F12°CPrecip 0.21 in5.4 mm36%Cloud 79%Wind NW 10 mph16 km/hFriday: Overcast and mild, with a high of 64°F18°C and morning low of 57°F14°C. Breezy from the NW at 10 mph16 km/h. 36% chance of light rain in the morning. Friday Night: Mostly cloudy, with a low around 54°F12°C. Breezy from the NW at 10 mph16 km/h. 34% chance of light rain overnight.
DrizzleHigh 62°F16°CLow 48°F9°CFeels 44°F7°CPrecip 0.06 in1.5 mm13%Cloud 49%Wind NNE 8 mph14 km/hSaturday: Mostly cloudy and mild, with a high of 62°F16°C and morning low of 48°F9°C. Breezy from the NE at 8 to 9 mph14 to 14 km/h. Dry air. Saturday Night: Partly cloudy, with a low around 49°F9°C. Breezy from the N at 9 mph14 km/h. 13% chance of drizzle overnight.

15-Day Forecast

Day High Low Precip Cloud Cover Condition Wind
SundaySep 2772°F22°C53°F12°C0 in0.1 mm· 9%66%Partly CloudyNNE 9 mph15 km/h
MondaySep 2867°F19°C56°F14°C0.04 in0.9 mm· 25%83%DrizzleN 6 mph10 km/h
TuesdaySep 2969°F21°C57°F14°C0 in0.1 mm· 1%65%Partly CloudyS 5 mph9 km/h
WednesdaySep 3069°F21°C58°F15°C0.04 in0.9 mm· 23%97%DrizzleSSW 8 mph13 km/h
ThursdayOct 173°F23°C64°F18°C0.17 in4.2 mm· 36%92%Light RainWSW 11 mph18 km/h
FridayOct 264°F18°C54°F12°C0.21 in5.4 mm· 36%79%Light RainNW 10 mph16 km/h
SaturdayOct 362°F16°C48°F9°C
Feels 44°F7°C
0.06 in1.5 mm· 13%49%DrizzleNNE 8 mph14 km/h
SundayOct 462°F17°C50°F10°C0.18 in4.6 mm· 26%67%ShowersSSE 9 mph15 km/h
MondayOct 558°F14°C47°F9°C
Feels 43°F6°C
0.06 in1.6 mm· 13%42%DrizzleWNW 11 mph18 km/h
TuesdayOct 659°F15°C43°F6°C
Feels 38°F3°C
0.02 in0.4 mm· 3%31%ClearW 9 mph14 km/h
WednesdayOct 763°F17°C47°F8°C
Feels 43°F6°C
0.02 in0.4 mm· 9%38%ClearSW 10 mph16 km/h
ThursdayOct 860°F16°C49°F9°C
Feels 45°F7°C
0.08 in2.1 mm· 22%46%ShowersW 11 mph17 km/h
FridayOct 957°F14°C45°F7°C
Feels 40°F5°C
0.05 in1.3 mm· 13%39%DrizzleW 10 mph17 km/h
SaturdayOct 1058°F14°C44°F7°C
Feels 38°F4°C
0.07 in1.9 mm· 14%44%DrizzleW 10 mph17 km/h
SundayOct 1158°F15°C46°F8°C
Feels 41°F5°C
0.09 in2.3 mm· 16%48%DrizzleWSW 10 mph17 km/h

Nearby Cities

About This Forecast

This forecast is powered by WeatherMesh, the world's most advanced and accurate weather model powered by AI. WeatherMesh is built on proprietary data from WindBorne's Global Sounding Balloon constellation — the world's largest fleet of autonomous, long-duration weather balloons — collecting observations across 100% of Earth, including over oceans and remote regions where no other data exists.

WeatherMesh consistently outperforms legacy models in independent benchmarks. View Benchmarks →

Access WeatherMesh forecasts programmatically via our API. API Documentation →

How to Access Weather Forecasts

PatternExampleDescription
/weather/{country}/{city}//weather/united-states/san-francisco/City forecast (canonical URL)
/weather/{city}//weather/tokyo/Shorthand — redirects to most populous match
/weather/{country}/{region}/{city}//weather/united-states/california/san-francisco/With region — redirects to canonical
/weather/nearby?lat={lat}&lon={lon}/weather/nearby?lat=48.1&lon=11.5Find nearest city by coordinates
/weather/{country}//weather/germany/Country index — all cities by region

Country and city names use lowercase slugs with hyphens (e.g. united-states, san-francisco). Arbitrary city names are supported — if not in our database, we geocode the name and serve the forecast for that location.

For programmatic access, use theWindBorne Forecast APIwhich returns structured JSON for any coordinates worldwide.

Coordinates: 43.8150°N, 79.4242°W·Elevation: 175m·Timezone: America/Toronto·Population: 115,292